front, some of the best foreign policy reporters in the business. david ignatius is with the "washington post," of course. tom ricks used to work for the "poat" is now contributing editor to "foreign policy" magazine and margaret brennan is our cbs news state department correspondent. before we get to foreign subjects here on earth, i want to talk about matters from outer space, and that meteorite that fell over siberia and injured over 1,000 people. so we're going back to new york to talk with the science editor and senior editor of "time" magazine jeffrey chewinger. jeffrey, let me start with the obvious. this thing caught our attention. there's no question about that. should we be worried about this? do these things pose a danger to those of us here on earth? >> well, they do and they don't. there's some comfort to be takenarchs we report in "time" magazine this week, that the earth has been playing in traffic for about 4 billion years now especially the time calmed the heavy bombardment period when the solar system hadn't quite acreeded yet. eve